This invention concerns a process for the hydrosilation of alpha-fluorinated olefins, in which selected cobalt compounds are used as catalysts.
The hydrosilation of olefins is a powerful and versatile method for the synthesis of various silicon compounds. Hydrosilation reactions using various silicon hydride and olefin combinations are known to be catalyzed by a variety of selected metal compounds, and in particular certain of the Group VIII metals have been found to be especially useful.
The hydrosilation of alpha-fluorinated olefins has been carried out using several Group VIII metal compounds [see for example I. Ojima, et al., J. Organometal. Chem., vol. 260, p. 335-346 (1984)].
However, in many of these reactions relatively poor yields of the simple hydrosilation product and/or relatively large amounts of other byproducts are obtained. It is believed that the highly electron withdrawing nature of the fluorine atom makes hydrosilation of alpha-fluorinated olefins difficult.
Cobalt compounds are known to effect hydrosilation of simple (unfluorinated) olefins, see for example J. F. Harrod and A. J. Chalk, J. Am. Chem. Soc., vol. 87, p. 1133 (1965). However, the hydrosilation of alphafluorinated olefins using cobalt compounds was not reported.